1. Field of the Invention
The apparatus of the present invention relates to measuring devices. More particularly, the apparatus of the present invention would relate to a coil tubing length measuring apparatus for measuring the length of coil tubing being inserted down a well hole.
2. Background of the Invention
In the drilling operations and production of oil and gas wells, it is very common that a particular apparatus or device must be inserted down the well hole in order to perform certain jobs and the completion of the oil well. Very frequently, what is required, is that the oil well be purged and any mud and/or debris, prior to the bringing up of oil or gas, which is being drilled for. During this purging process, for example, flexible metal tubing is inserted down into the well hole to a very precise depth at which time highly pressurized liquid or fluid nitrogen is inserted into the tubing down into the well hole in order to purge out the well and to possibly drive back the oil or gas in the cavity of the well hole in order to seal off the hole in order to bring up more purified oil and gas. Also, this tubing may enable the production crew to insert various types of lubricants, etc., which would assist in the production of oil and gas.
What is crucial about this process, is that the tubing be inserted to this precise depth, so that the production crew is knowledgable that when the fluids which are being inserted down through tubing reach the end of the tubing, that these fluids have ben carried down to a precise depth within the hole.
Several apparatuses have been patented which may speak to a device which could be utilized for this purpose. However, of the patents in this particular art, those which have been patented are rather limited in their use, and have shortcomings which will be discussed further.
U.S. Pat. No. 3,411,350 entitled "Cable Length and Tension Indicating Apparatus" issued to M. T. Sokolosky, discloses a cable length and tension measuring apparatus comprising a rigid supporting frame, a measuring wheel mounted on the frame, an indicator means for the tension and length measuring means. In this particular apparatus, the pair of the guide wheels are tensionly mounted, in order to guide the cable along the drive wheel.
U.S. Pat. No. 2,154,621 entitled "Measuring Instrument" issued to C. R. Jenkins would provide for a measuring wheel in which the cable or rope to be measured is held to the wheel by rollers rigidly affixed to an arm. In this particular apparatus, one of the rollers is adjustable along a certain area for imparting additional tension on the cable.
U.S. Pat. No. 3,068,479 entitled "Line Measuring and Movement Indicating Device" issued to J. L. Newman provides for a measuring wheel and means for preventing lateral movement of a cable or line as the line moves longitudinally in contact with the measuring wheel from one end of the guide to the other.
U.S. Pat. No. 2,940,173 entitled "Trawl Cable Meter" issued to C. A. Crecelius provides for a cable meter which comprises a housing to which a cable can be drawn to which is rigidly attached rollers mounted in tandum for rolling the cable on and a wheel for holding the cable against the rolling means. This particular apparatus would be used during trawling operations in fishing.
U.S. Pat. No. 2,060,233 entitled "Measure Meter" issued to C. A. Mathey et al provides for a meter for measuring the length of cable that passes therethrough. There is provided a plurality of wheel counters which are supported by a rigid frame.
U.S. Pat. No. 1,481,980 entitled "Cable Measuring Device" issued to R. R. Bostic provides for a wheel counter supported by a rigid frame to which is also rigidly attached a second wheel or idler for regulating the path of cable to be measured.
U.S. Pat. No. 2,327,506 and 2,136,457 also disclose measuring devices which comprise wheels, pulleys and cables in this particular field of the art.
In general, the above cited patents failed to fulfill the needs as required in this particular field of endeavor. That is, the measuring apparatus must very accurately measure the amount of cable or tubing being pulled through the apparatus, and must provide for an adjustable amount of tension between the driver wheel and idle wheels.
3. General Discussion of the Present Invention
The present invention would solve the problems and the present state of the art shortcomings thereof in a simple and inexpensive, straightforward manner. The present invention would provide for an apparatus for measuring the longitudinal distance of cable or tubing, having a unitary support frame with a first end having a pair of broad support arms for rotatably mounting a measuring wheel therebetween, with the support arms generally comprising a unitary base support structure. There is a second end having a pair of mounting arms, in substantially parallel relationship and integrally connected to the spport structure. Also is provided a secondary support frame substantially transversely mounted between the pair of mounting arms, and adjustable in an upward and downward path, a pair of grooved guide wheels rotatably mounted on each end of the transverse secondary frame, and a means for engaging the tube to be measured between the pair of grooved wheels and the measuring wheel, with that means being an adjustable means for imparting a predictable amount of tension between the idle wheels and the measuring wheel. Engaged onto the measuring wheel is a counter means for numerically registering the length of tubing travelling along the measuring wheel, with a read-out being directly the result of the number of feet or meters travelled by the coil tubing along the measuring wheel.
Thus, it is an object of the present invention to provide a simple and inexpensive apparatus for measuring the longitudinal distance of cable or tubing being inserted down into a well hole.
It is another object of the present invention to provide an apparatus which is generally comprised of a unitary support frame housing with a measuring wheel with idle wheels mounted thereupon.
It is a further object of the present invention to provide an apparatus wherein selective amounts of tension may be imparted between the idle wheels and guide wheel for measuring the length of tubing being passed therethrough.
It is a further object of the present invention to provide an apparatus wherein the idle wheels are able to maneuver up and down in order to adjust to the movement of the tubing as it is travelling through the apparatus, always keeping the center line of tension constant.
It is still a further object of the present invention to provide an apparatus wherein the counter which reflects the length of tubing travelled may be mounted on either the right or left side of the apparatus, depending on the situation.